Fluid-cushioned artificial leg



Nov. 3, 1953 J. HALLER 2,657,393

FLUID-CUSHION@ ARTIFICIAL LEG Filed June 21, 1952 2 sheets-sheet 1:inventor C orneg NOV. 3, 1953 J. HALLER l 2,657,393

FLUID-CUSHIONED ARTIFICIAL LEG Buncnfor ornegs Patented Nov. 3, 1953 UNITED STATES FF l 2,657,383

FLUID-CUSHIONED ARTIFICIAL LEG` John 'Haller2 Northville, Mich.Application .lune 21, 1952, Serial N o. 234,821

8 Claims. 1

This invention relates :to articial limbs and. in particular, toartificial legs.

One object of this invention is to provide a fluidecushioned artificialleg enabling the wearer to obtain a smooth vand even heel andtoe ac tionofthe foot together with a desired amount of resistance to such action,this resistance being adjustable to provide a stiff action vfor a heavyperson or alight action for a lightweight Person.

Anothervobject is to provide a fluid-.cushioned artificial leg of .the'foregoing character, wherein the cushioning :action Ais brought abouttby the reciprocation of a piston Within the ankle portion of theartiiicial leg in response to the rocking of the foot portion, the flowof lludresulting from the reciprocation of ythe piston beingcontrolled'by an adjustable resistance'rnember, such as a spring-pressedvalve which yieldingly opposes the free vflow of such fluid with apredetermined resistance.

Another object is to provide a .fluid.cushioned artificial leg of theforegoing character wherein the -reciprocating piston is also yieldinglyopposed, as by a compression spring which returns the piston to itsstarting point when the foot rocks hack to its neutral position between'the extreme forwardvand rearward portions of the stride.

Other objects and advantages of the invention will :become apparentduring the course oi the following description of the accompanyingdrawings, wherein:

Figure 1 is a side elevation, mainly in `central vertical section, ofthe lower portion of afinidcushioned articial leg Vin its neutralposition according to one Aform of theinvention;

Figure 2 is a .horizontal lsection taken along the line 2--2in Figure 1;

Figure 3 is a view similar tUFigure. lfbut show ing the positions of theparts when the f oot is at the forward end of its vforward Stride; and

Figure 4 is an enlarged fragmentary view of one of the ball check valvesvof Figure 1, Asljlowing the bypass grooves therein.

Referring to the drawings in detail, Figure l shows a duid-cushionedartificial leg, generally designated Ill, the upper portion being oficonventional construction, particularly as regards its means ofattachment .to the stump of the living leg remaining after amputation.The articialleg I is provided with a fluid-operated cushioning device,generally `designated I I, mounted in the ankle portion I2 of the legIl) to which the foot portion, generally designated I3, is pivoted, asat thepivot yjoint I4.

The foot. portion 1.3, is shaped like e. human fooi, lso as to maten:the weareris other 4foot in sizeand shape, except that awedge-shapedeleorance is provided between the iorward and yFedra Wardportions or toev `and heel porti, s l5. and i6. by providingwedge-shaped cops between the upper flat surfaces Il and I8 of the lroetpore tion I3. and the lower flat surfaces I3 and 2Q of the ankle portionI2.V The portions II and I8 are inclined at olotoseonele to one oriotheras .are the ankle portions i9 and 2U, in order to. provide theseWedge-.Shaped Clearance spaces l2l and 22 facilitating vnormal strilingor walking motion by permitting lrookins of; the foot portion I?.relatively te the ookle portion I2 around the pivot joint I4.

The pivot joint Ii consists of e peil oi aligned vertical bores 25 and26 in the foot and ankle portions I3 and I2 respectively, thesereceivingbali and socketloolts. 2l and 2 8 respeotivelv- The ball bolt21 is anchored in `position by a nut 2Sl mounted in e ooontersnk 3l! andprovided with wrench or spanner holes 3l by which its threaded bore '3 2is threaded upon the threaded portion as of the toit 21. The upper end0f the bore 2 5 terminates a spherical clearance lrecess 35 above whichthe ball head 36 of the ball .bolt 2l projects.

The ball hood 3691s, Provided with a spherical convex surface il whichis Seated in a correspending spherical concave surface 38 provided in ahollow spheriool shell portion 3Sy on the. lower end of the socket bolt28. The outer suriace 40 of the spherical shell 39 has a Sphericalcurvature concentric with the curvature of the surfaoes 3,'I, 38 and 35and closely fitting the spherical surface 35 inthe rocking action of thefcot portion I3. relatively tothe ankle portion IZ. The shell portion 39is seated Vinra spherical socket 4I in the lower end of theanklefportion I2 whereas lthe `upper end of the socket bolt 28 threadedas yat Yd2 to receive a retaining nut 43 and .passes Vthrough a hole 44in the lower end or head d5 of a fluid cylinder 46.

The upper suriaoes I1 Iend I8 of the toot portion I-3 are provided withcup-shaped, sockets 50 and 5I vrespedilvely reoeivinehardened metalContact plugs or -lodttons 52 ond 53 respectively located at' shortdistances from the center del of the ball head 3.6; Engaging theoontaotbut: tons 52 dhd53 are the rounded lower ends 5,5 and 56 respectively ofreoiproooble metiera-trans,- mittine rods 5l and 58 reoiprooablv mountedin bores 5S Vand BIJ located Yvvithrtheir axes parallel to and spaoedeouidistontly from the exis of the socket bolt Zd. The vrods 5l `and 58pass actress l. 3 through holes 6| and 62 in the cylinder head 45aligned with the bores 59 and 60.

The fluid cylinder 46 is mounted in a cylindrical socket or bore 65opening into a hollow 55 within the upper part of the ankle portion 12,and is provided with an outer cylinder bore l|51, the upper end of whichis threaded as at 68 and closed by a threaded plug or head 69 threadedtherein as at and provided with wrench or spanner sockets 1|. On itsunderside, the head 69 is provided with a cylindrical recess 12receiving a spring abutment collar 13 of similar conguration and havinga central bore 14 opening into a counterbore in its upper end. Passingthrough the bore 14 and having its upper end seated in a coaxialcounter-bore 16 in the cylinder head or plug B9 is a hollow tubular stem11 having an annular recess 18 near its upper end engaged by a snap ring19 mounted in the counterbore 15. The spring abutment collar 13 isprovided with a reduced diameter portion 80 having a surrounding annularshoulder 8| which serves as an abutment for the upper end of a helicalcompression spring 82.

The lower end of the compression spring B2 engages an annular abutmentshoulder 95 on a closure head 86 which is provided with a threadedportion 81 :by which it is threaded into the correspondingly threadedportion 88 at the upper end of an inner cylinder bore 99 within a hollowpiston 90 reciprocably mounted within the outer cylinder bore 61. Agasket 9| of yieldable material, such as rubber or synthetic rubber,prevents fluid leakage and provides resilience at this location. Themidportion of the tubular stem 11 passes through a bore 92 in theclosure head 88 of the hollow piston 90 and emerges within the innercylinder bore 89 where it is provided with an enlargement 93 having anannular abutment surface 94 beneathwhich the stem 11 is provided with anextension 95. The closure head 86 of the piston 90 is provided with anannular recess 95 receiving a so-called O-ring 91 of elastic deformablematerial such as rubber or synthetic rubber and this is held in positionby a retaining ring 98 mounted in a recess 99 by means of screws |90.

Mounted on the extension 95 of the hollow or tubular stem 11 is anannular stationary inner piston head |0| with its upper end |02 engagingthe abutment shoulder 94 and with its midportion provided with anannular recess 103 also receiving an O-ring |04 of elastic deformablematerial such as natural or synthetic rubber, in order to prevent fluidleakage between the piston 90 and cylinder 45. The piston head |01 isheld in position by a snap ring |05 seated in an annular recess |06 inthe lower end of the stem extension 95 and engaging a port ring |01provided with a plurality of circumferentially-spaced lower uid ports|08 (one only being shown). The port ring |01 is secured in an annularrecess |09 in the lower end of the inner piston head |0| by means ofscrews ||0.

Immediately above the ports 108, the inner piston head |0| is providedwith a corresponding number of cylindrical ball valve chambers'Hl, eachof which contains a vertically reciprocable ball check valve member |12.The ball check valve members 112 are movable upward against seatsconsisting of the lower ends of upper uid ports 113 which extend fromthe upper ends of the ball valve chambers |11 into radialhalf-teardrop-shaped fluid passages ||4 leading past the annularabutment surface 94 into the upper end of the inner cylinder bore 4 89.The upper ends of the lower uid ports |08 are prevented from beingclosed by the balls |12 by the provision of bypass grooves 109e formedtherein.

Extending upward through the tubular stem extension 95 from the lowerpart of the inner cylinder bore B9 is a central fluid passageway l5, theupper end of which serves as a ball valve seat in an enlarged vbore |19,the lower portion of which is smooth and the upper portion threaded.Running from the ball chamber |15 radially through the stem Yenlargement 93 to the upper portion of the inner cylinder bore 89 is afluid passageway |11. Reciprocably mounted in the lower end of theenlarged bore H8 is a ball check Valve member |18 which is urgeddownwardly by a headed pin |19 which itself is urged downwardly by ahelical compression spring |20 mounted in the hollow stem bore H5. Theupper end of the spring 120 abuts against the lower end of a screw plug12| threaded into the threaded upper portion of the bore |19, andadjustable by means of an ordinary screw driver.

The upper end of the stem bore |16 is closed by a screw plug |22threaded into the upper end thereof and having its head seated in arecess |23 in the cylinder head 09. Thus the screw |22 also holds thetubular stem 11 within the counterbore 15. A fluid passageway or bleederhole |28 extends obliquely upward from the space above the piston head10| within the stem enlargement 93 into the portion of the stem bore w|16 above the spring abutment pin |19 to release duid leaking past thepin |19.

The inner piston head |0| and the stem enlargement 93 are made in twopieces in order to provide convenient machining of the passageways 1M.It is possible, however, to form the `head |0|'integral with the stemenlargement 93 by rendering this machining operation somewhat morecomplicated.

In the operation of the invention, let it be assumed that the leg 10 isstrapped or otherwise attached by conventional means (not shown) to thestump of the amputated leg and is, of course, of suflicient length forthat purpose. By previously having removed the sealing plug |22 from theupper end of the bore 1 16 within the tubular stem 11, the adjustingscrew |21 is screwed upward or downward to increase or decrease theforce exerted by the helical spring |20 upon the contact pin |19 whichengages the ball check valve IIB, until the desired resistance isobtained to Y the flow of fluid upward through the passageway.

Let it be assumed that the wearer thrusts his leg forward to begin towalk, placing his weight upon the heel portion I8 of the foot 13. Thisaction (Figure 3) causes the foot 13 to rock about the pivot joint 14,forcing the motion-transmitting rod 53 upward and consequently pushingthe hollow piston upward in the cylinder bore 81, toward the stationaryinner piston 10 compressing the spring 82. The fluid trapped below thepiston head |0| is forced upward through the passageway 1 I5, raisingthe ball check valve |18 oil its seat at the upper end of the passageway||5 and thereby overcoming the thrust of the spring |20 and compressingit (Figure 3). This permits the fluid to pass from the passageway ||5through the passageway ||1 into the upper end of the inner cylinder bore89. As the passageways |15 and |11 are constricted, the action iscushioned by the spurting of the iluid, such as oil, through theseconstricted passageways ||5 and |11. Meanwhile, the ball check valve 5't #-2 hasfrisen, havin'g'beenv forcedl upwar'dby f iluid passingthrough the `passageways TI'8 into the chamber lfllfcausing fthe ball H2'to -seal the lower-*ends of the passageways fl |`3 (Figure 3).

JlAs-"thefoot f3 rocks about the pivot `joint Vi4 during the-completionof the'stride, the-'rearward piston rod 'i5'8 iis lpushed downward -inresponse to 'the pushing 4downward of the hollow pistonS'Oibythecompression spring 82 and "fluid passes from ftheupper partofthe1innerbore`89 to the lower part'thereof by way Vof the radialpassage- Ways llfdand vthe passageways H3 and |08 past the ball valves|I`2. After the foot passes vthe neutral for mid-stride vposition(Figure l), the rodliljis pushed upward, again' pushing l the-hollow'lpi's'tonlwupward and compressing the spring 82 while againforcing the ball rcheck valve H8 off its seat in compressing its springI20,'again releasing fluid to pass through the passageways H5 and IIIinto the upper part of the inner cylinder bore 89 in the same manner asdescribed in connection with Figure 3. This again exerts a. cushioningaction in the same way as described above. When the walker reaches therearward end of his stride and starts forward again, the foot I3 againrocks through the neutral position of Figure 1 to the forward positionof Figure 3, repeating the foregoing operations.

What I claim is:

l. A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston fixedly mounted in said innercylinder bore, said stationary piston having a restricted forward fluidpassageway and a return fluid passageway therethrough, and amotion-transmitting element extending from said foot member through saidcylinder to said movable piston and responsive to the rocking of saidfoot member for reciprocating said movable piston in said cylinder.

2. A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston xedly mounted in said innercylinder bore, said stationary piston having a forward fluid passagewayand a return fluid passageway therethrough, a one-way valve disposed inone of said passageways permitting only unidirectional uid ilowtherethrough, and a motion-transmitting element extending from said footmember through said cylinder to said movable piston and responsive tothe rocking of said foot member for reciprocating said movable piston insaid cylinder.

3. A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston flxedly mounted in said innercylinder bore, said stationary piston having a forward fluid passagewayand a return fluid passageway therethrough, a one-Way valve disposed ineach of said passages. ways VIpermitting only unidirectional -fluid'fowtherethrough, anda motion-transmittingI element extending from-'saidfoot member throughlfs'aid cylinder to' saidfmovable'piston` andresponsiveto the rocking of said-foot memberfor reciprocatingsaid'movable piston in said cylinder.

4. A 'duid-cushioned?articial leg comprising a-leg member, 'a'foot'member pivotallyl attached to--saidlegmember for rockingmotionrelatively thereto, alfluidfcylinder-mounted in one "of saidmembers and having an outer cylinder bore therealhollow 'movable' pistonreciprocablymounted in said outercylinder'bore and having lain-innercylinder bore therein, -a stationary piston fflxedly mountedlinsaidinner cylinder bore, said-'stationary piston lhaving* aforwardfluid 'passageway and fa return 'fluid passageway therethrough-a one-wayvalvefdisposediin each 'o'f said passageways permitting onlyunidirectional fluid flow therethrough, a resilient element engaging andyieldingly urging one of said valves into its closed position, and amotion-transmitting element extending from said foot member through saidcylinder to said movable piston and responsive to the rocking of saidfoot member for reciprocating said movable piston in said cylinder.

5. A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston fixedly mounted in said innercylinder bore, said stationary piston having a restricted forward fluidpassageway and a return fluid passageway therethrough, and amotion-transmitting element extending from said foot member through saidcylinder to said movable piston and responsive to the rocking of saidfoot member for reciprocating said movable piston in said cylinder, anda resilient member yieldingly engaging and urging said piston againstsaid motion-transmitting element.

6. A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston flxedly mounted in said innercylinder bore, said stat1onary piston having a forward fluid passagewayand a, return fluid passageway therethrough, a one-way valve disposed inone of said passageways permitting only unidirectional fluid owtherethrough, a motion-transmitting element extending from said footmember through said cylinder to said movable piston and responsive tothe rocking of said foot member for reciprocating said movable piston insaid cylinder, and a resilient member yieldingly engaging and urgingsaid piston against said motion-transmitting element.

7 A fluid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a fluid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having' an innercylinder bore therein, a stationary piston xedly mounted in said innercylinder bore, said stationary piston having a forward fluid passage.

Way and a return uid passageway therethrough, a one-way valve disposedin each of said passage- Ways permitting only unidirectional fluid flowtherethrough, a motion-transmitting element extending from said footmember through said cylinder to said movable piston and responsive tothe rocking of said foot member for reciprocating said movable piston insaid cylinder, and a resilient member yieldingly engaging and urgingsaid piston against said motion-transmitting element.

8. A huid-cushioned artificial leg comprising a leg member, a footmember pivotally attached to said leg member for rocking motionrelatively thereto, a uid cylinder mounted in one of said members andhaving an outer cylinder bore therein, a hollow movable pistonreciprocably mounted in said outer cylinder bore and having an innercylinder bore therein, a stationary piston fixedly mounted in said innercylinder bore, said stationary piston having a forward fluid passagewayand a return fluid passageway therethrough, a one- Way valve disposed ineach of said passageways permitting only unidirectional fluid flowtherethrough, a resilient element engaging and yieldingly urging one ofsaid valves into its closed position, a motion-transmitting elementextending from said foot member through said cylinder to said movablepiston and responsive to the rocking of said foot member forreciprocating said movable piston in said cylinder, and a resilientmember yieldingly engaging and urging said piston against saidmotion-transmitting element.

JOHN I-IALLER.

No references cited.

